a) Field of the Invention
The present invention relates to a diaphragm pump.
b) Description of the Prior Art
A conventional diaphragm pump is configured as shown in FIG. 1. In this drawing, a reference numeral 21 represents a motor, a reference numeral 22 designates an output shaft of the motor 21, a reference numeral 23 denotes a crank base which is fixed to the output shaft 22, a reference numeral 24 represents a driving shaft which is fixed to the crank base 23 in an inclined condition, a reference numeral 26 designates a driving body which is rotatably attached to the driving shaft 24, a reference numeral 27 denotes a casing, a reference numeral 28 represents a cylinder member and a reference numeral 29 designates a valve housing. A reference numeral 31 represents a diaphragm member and a reference numeral 32 designates a cylindrical discharge valve; the diaphragm portion and the discharge valve 32 being integrated to compose a diaphragm main body 30. This diaphragm main body 30 is held by the cylinder member 28 and the valve housing 29. Furthermore, reference numerals 33 and 34 represent a valve chamber member (common chamber) and a discharge port which are formed integrally with the valve housing 29, a reference numeral 35 designates an air intake valve and a reference numeral 36 denotes an air intake port.
The diaphragm pump which has the above described configuration rotates the crank base 23 when the output shaft 22 is driven and rotated by the motor 21. Rotation of the crank base 23 changes a direction of inclination of the driving shaft 24 which is fixed to the crank base 23. Accordingly, a direction of inclination of the driving body 26 is also changed and a driving portion (piston) 31a of the diaphragm member 31 reciprocates, thereby performing a pumping action. When the driving portion 31a is raised like a diaphragm member on the right side in FIG. 1, a capacity of a pump chamber is reduced and a pressure is changed in this chamber, whereby the cylindrical discharge valve 32 is opened and a fluid is sent out of discharge port 34. When a driving portion is lowered like a left side diaphragm member, on the other hand, a capacity of a pump chamber for this diaphragm member is increased, whereby external fluid opens the air intake valve 35 and flows into the pump chamber.
The diaphragm pump performs a pumping action by changing capacities of the pump chambers as described above, thereby allowing the fluid to flow from outside into the pump chamber through the air intake valve, and then allowing the inflow fluid to open the discharge port and to be supplied from the discharge port.
Since the above described conventional diaphragm pump uses the cylindrical discharge valve which is formed integrally with the diaphragm member, a portion composing the valve chamber portion (common chamber) in which this cylindrical valve is disposed is similarly cylindrical, protrudes from a surface portion of a cover body, has a discharge port extending from an upper end surface of the valve chamber portion, and is used in a condition where a pipe or the like is connected to this discharge port for leading the fluid to a location of supply.
Since the conventional diaphragm pump protrudes outside from the above described cylindrical portion composing at least the valve chamber portion (common chamber), the conventional diaphragm pump is obliged to have a relatively large and stepped form. Accordingly, the diaphragm pump is limited in its location of installation in rare cases.
Furthermore, the conventional diaphragm pump which uses the cylindrical discharge valve has a defect that it allows the cylindrical discharge valve to be deformed during part custody, transportation and the like before assembling the pump after manufacturing the valve. Furthermore, the cylindrical valve is thin and therefore poses a problem associated with assembly that the pump required tedious works to insert the cylindrical valve into the valve chamber portion (common chamber) at a pump assembling stage and the like.